Prime Minister Lester B. Pearson speaks at a press conference in Ottawa on Dec. 14, 1967. He was the last prime minister to see active duty. He was both a member of the Canadian Army Medical Corps during the First World War and then a pilot in Britain. THE CANADIAN PRESS/Peter Bregg

As he goes from door to door wooing byelection voters in southwestern Ontario, Erin O'Toole talks about a lot of different issues, with one pointed exception: his 12 years as a member of the Canadian Forces.

O'Toole, the Conservative hopeful in the riding of Durham, is fiercely proud of his time in the Royal Canadian Air Force and the Navy, which included Sea King helicopter missions after the 1998 crash of Swissair Flight 111.

It's just that he doesn't want to be seen as using his military service or work with veterans as a springboard to a political career.

"When you leave the military, you feel a sense of guilt because your friends are still there, they are still serving," said O'Toole, who traded the life of a soldier for law school in 2000.

His desire to be in public life comes from somewhere else, he suggested.

That reluctance to highlight a military resume, while seemingly common in Canada, is at odds with politicians in the United States, where time in the armed forces is often seen as a prerequisite of sorts for running for office.

That could be changing, this year marked the first presidential election since 1932 where neither the Democrats or Republicans had a veteran running for president or vice president.

But for whatever reason, Canada has seen a far smaller proportion of ex-soldiers choosing to throw their berets into the political ring.

Over the history of the House of Commons, only 18 per cent of the 4,202 MPs ever elected have military duty on their resume, according to statistics on the parliamentary website.

Among them was George Baker, elected as a Tory in 1911 as the Canadian government decided to join the British effort in the First World War. He then joined the military and was the commander of the 5th Canadian Mounted Rifles when he was killed in action at Ypres in July 1915.

The majority of MPs who have military records come from the First and Second World Wars, when collectively about 2 million Canadians served in the forces.

As the number of Canadians serving has dwindled, so too has the number of politicians drawn from their ranks, said military historian Christian Leuprecht.

"In the U.S., the military has a strong linkage with society, 1 in 8 Americans will serve at some point in their lifetime," he said via email from a conference in Spain.

"In Canada, it's closer to 1 in 100. It just doesn't have the same cache as it does in the U.S."

Of the 43 men who have served as U.S. president, only 11 have zero military experience on their resume. By contrast, of the 22 Canadian prime ministers, 15 have never done military duty.

The last prime minister to see active duty was Lester Pearson, who was both a member of the Canadian Army Medical Corps during the First World War and then a pilot in Britain.

Thirteen current MPs list some military service in their official backgrounds: two are Liberals, five are New Democrats and six are Conservatives.

Only one is a veteran of Canada's most recent conflict, the war in Afghanistan.

Tory MP Corneliu Chisu did one rotation in Kandahar as an engineer, responsible for setting up the Canadian compound and bases in the province. He also served in Bosnia.